This invention relates to arrangements of valves to control fluid flow, and in particular to such valve arrangements which provide protection from accidental intermixing of the fluids.
In the past it has been customary to fill a vat of a food liquid, such as a vat of milk, or pharmaceuticals, or soft drinks, from the top, such as through a spray ball, and to drain it from the bottom. This was true because regulations require strict separation of the raw materials pumped into the vat from the product drained from the vat after processing inside the vat. Regulations also require strict separation of both the raw materials and the products from the cleaning solution with which the vat is flushed after draining of the product. To date this strict separation has not been possible with a single fill/drain inlet at the bottom of the vat. Further sanitary regulations require the provision of a full bore leak port, to enhance the above mentioned separation even more.
Moreover, the conventional top fill method often has undesirable side effects, in that substantial aeration of the fluid could occur during filling. Depending on the type of fluid being filled into the vat, the result of this aeration could be foaming and substantial reduction of filling efficiency.
This invention relates to improvements over the apparatus set forth above and to solutions to the problems raised or not solved thereby.